Combination lock

ABSTRACT

A combination lock having a rotor, mounted in a casing, and which carries locking elements arranged in lengthwise extending slots on the outer surface thereof, the locking elements each being manipulatable, by suitable mechanism, to cause movement between first and second longitudinally spaced dispositions, each element in one disposition precluding rotation of the rotor by engagement with an abutment on the internal surface of the casing and in the other disposition clearing the abutment so as not to preclude rotation, the rotation precluding condition for some elements normally corresponding to one disposition, and for others normally corresponding to the second disposition.

United States Patent Marotte 451 June 20, 1972 [s41 COMBINATION LOCK[22] Filed: July 28, 1970 [21] Appl.No.: 58,966

FORElGN PATENTS OR APPLICATIONS 183,377 7/1922 Great Britain. ..70/299156,646 5/1954 Australia ..70/299 Primary ExaminerAlbert G. Craig, Jr.Attorney-Waters, Roditi, Schwartz & Nissen [57] ABSTRACT A combinationlock having a rotor, mounted in a casing, and which carries lockingelements arranged in lengthwise extending slots on the outer surfacethereof, thelocking elements each being manipulatable, by suitablemechanism, to cause movement between first and second longitudinallyspaced dispositions, each element in one disposition precluding rotationof the rotor by engagement with an abutment on the internal surface ofthe casing and in the other disposition clearing the abutment so as notto preclude rotation, the rotation precluding condition for someelements normally corresponding to one disposition, and for othersnormally corresponding to the second disposition.

16-Claims, 20 Drawing Figures PATENTED JUH 2 0 1972 SHEET 10F 4PATENTEuJum m2 3, 670,539

sum 3 0F 4 COMBINATION LOCK BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to combination locks.

2. Description of the Prior Art It is well known that combination lockspossess a number of advantages over the more commonly used domestictypes of lock, not the least of which is that no difficulties can arisethrough lost keys. However, since efficient combination locks havehitherto been relatively complicated and expensive it has not beencustomary to use combination locks for ordinary domestic purposes.

It is an object of the invention to provide an improved combination lockwhich is of comparatively simple construction and which may bemanufactured relatively cheaply so as to render practicable its use indomestic applications.

Aside from the above-mentioned cost and complexity of the commoncombination locks, many of these offer the further disadvantage that itis possible to detect when the individual locking elements are releasedbecause of noises made during release. It is possible for a skilledperson to open these locks by manipulating the locking mechanism andlistening for the operation of the locking elements. Another object ofthe invention is therefore to provide a lock which may be easilyarranged to at least substantially eliminate this drawback.

BRIEF SUMMARY OF THE INVENTION In accordance with this invention theabove objects are attained by a lock construction in which the lockingelements are slidable between locked and unlocked positions.Specifically the invention provides a combination lock having a casingstructure, a rotor mounted for rotation within said structure, aplurality of locking elements carried by one of said rotor and casingstructure and actuating means, said locking elements each being slidablebetween first and second locations and each, inone of these locations,preventing substantial rotation of said rotor within said casingstructure and in the other location not precluding such rotation, saidactuating means being operable to move said elements or any selected oneor more thereof one by one from the first location to the secondlocation.

Normally the locking elements are carried by the rotor. The lockingelements preferably cooperate, in the rotation precluding condition,with abutments on that one of the rotor and casing structure which doesnot carry the locking elements.

The above described lock construction is relatively simple and themovement of each locking element, effected by the said actuating means,may be arranged to be the same regardless of whether the elements arebeing moved into or out of a locking position, so that it is notpossible to detect audibly the result of any such movement of theelement.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is aperspective view of a lock constructed in accordance with the invention;

FIG. 2 is a longitudinal cross-section of the lock shown in FIG. 1, thelock being shown in the condition in which the rotor is free;

' FIG. 3 is a longitudinal cross-section of the line 3-3 of FIG.

FIG. 4 is a transverse cross-section on the line 44 of FIG.

FIG. 5 is a transverse cross-section on the line 5-5 of FIG.

FIG. 6 is a transverse cross-section on the line 6-6 of FIG.

FIG. 7 is a transverse cross-section on the line 7-7 of FIG.

FIG. 8 is a fragmentary cross-section corresponding to FIG. 2 butillustrating the position of the knob immediately before the dialingoperation;

FIG. 9 is a cross-section corresponding to FIG. 2 but showing the mannerin which shifting of the locking elements is accomplished;

FIG. 10 is a cross-section corresponding to FIG. 7 but illustrating theposition of the knob when it is turned to operate the latch;

FIG. 11 is a transverse cross-section corresponding to FIG. 2 butillustrating the manner in which resetting of the lock is accomplished;

FIG. 12 is a longitudinal cross-section corresponding to FIG. 3 butillustrating the lock in a condition in which the rotor is freed but hasnot been actuated;

FIG. 13 is a perspective view of the casing of the lock shown in FIG. 1;

FIG. 14 is a perspective view of a rotor incorporated in the lock shownin FIG. 1 partly broken away to illustrate the interior;

FIG. 15 is a perspective view of a pair of abutment members incorporatedin the lock shown in FIG. 1;

FIG. 16 is a perspective view of a locking element incorporated in thelock shown in FIG. 1;

FIG. 17 is a perspective view of portion of the knob assembly of thelock shown in FIG. 1;

FIG. 18 is a perspective view of another part of the knob assemblyincorporated in the lock shown in FIG. 1;

FIG. 19 is a perspective view of a lever element incorporated in therotor of the lock of FIG. 1;

FIG. 20 is a perspective view of a catch member incorporated in the lockshown in FIG. 1.

DETAILED DESCRIPTION The lock shown comprises a casing 14 within whichis located a rotor structure 15. The lock 14 has an actuating knob 110at one end. This end is, in the ensuing description, referred to as theforward end of the lock and any usage in this description, or in theappended claims, of forward" or rearward or like positional terms is tobe construed accordingly. It is to be understood that this usage ismerely to simplify terminology and is not to be construed as limiting.

Rotor structure 15 is illustrated in FIG. 14. It comprises anintermediate, generally cylindrical, part 17 from one end of whichextends an integral shaft 18. A skirt portion 19 of annularcross-section extends rearwardly from the other end of part 17. Threeperipheral grooves 20, 21, 22 are provided in the outer surface of part17 and a plurality of slots 23 extend lengthwise thereof. Each slotextends radially and is of generally rectangular in cross-section.

Portions of the slots at the forward end of part 17 are enlarged bycircular bores 24. There are, in the present embodiment ll equi-spacedcircular bores 24 but only 10 slots 23. The bore 24 which is notassociated with a slot 23, instead, leads into another radiallyextending slot 27 in intermediate part 17. Slot 27 is different inconfiguration to slot 23 and extends inwardly from the outer surface ofportion 17. A bore 28 extends coaxially within the rotor and slot 27extends into this. Bore 28 is enlarged at its rearmost end to define theinner surface of skirt 19.

The slots 23 extend over the whole longitudinal length of part 17, andthe enlarged portion 29 of bore 28 also extends into these, so that ashoulder 31, at the plane of disjunction between the narrower andenlarged portions of bore 28, is spaced a short distance forwardly ofthe rear end of the slots.

Shaft 18 is provided with a slot 32 at its forward end. This slot isgenerally rectangular in transverse cross-section and extends radiallyof the shaft. Shaft 18 is also provided with two radial bores 34, 35.These are tapped and a pin 58 is threadably engaged in one of them. Asis best seen from FIG. 7 the axes of the two bores 34, 35 are displacedfrom each other. The purposes of these bores, and of pin 58 are detailedhereinafter.

Within each slot 23 is a separate locking element 36. The lockingelements are all of identical form and one is illustrated in FIG. 16.Each is of elongate rectangular form and is provided with a cut outportion 37 which extends from one edge face of the element. The sidewall 38 of this cut out portion is disposed midway between the two endfaces 39, 41 of the element and the elements are placed within the slots23 with the cut out portions 37 facing outwardly and with either a face41 or a face 39 disposed towards the forward face 30 of part 17 on rotor15.

The selection of which ends 39 or 41 of the various members are disposedtowards face 30 is determined by the lock combination as is hereinafterdescribed. The elements 36 are each slidable axially of the length ofrotor 15 and are retained within the rotor by means of a circularhelical spring 42 which is housed in groove 20 in rotor 15. This springbears lightly against the outer edge faces 43 of the elements 36.

The elements are of lesser length than the length of slots 23 and aremovable between two lengthwise displaced positions (see FIG. 12 forexample). In one of these positions those faces of the elements whichare to the rear of the lock abut against the rear end face 40 of theslots 23. In the other position the rearmost faces are aligned in theplane of the shoulder 31 on rotor 15. The cut out portions 37 arealigned with the centrally placed groove 21 on part 17 in either one ofthe two lengthwise displaced positions depending upon the specificorientation of the elements 36 in their slots. In particular, each ofthe elements 36 which is arranged with its face 39 to the rear will haveits cut out portion 37 aligned with groove 21 when it is in a forwarddisplaced position, illustrated for example by the upper element in FIG.12. On the other hand, each of the elements 36 which has its face 41 tothe rear will have its cut out portion 37 aligned with groove 21 when itis in a rearmost position as illustrated by the lower element 36 shownin FIG. 12.

A resetting member 46 is mounted within rotor 15. It comprises a firstcylindrical shaft portion 47 which is engaged within bore 28 and anenlarged head 48 of circular cross-section. Head 48 is of somewhatlesser diameter than the interior diameter of skirt portion 19 but ofgreater radius than the distance between the innermost radial faces 45of the slots 23 and the axis of the rotor. The shaft portion 47 ofmember 46 is provided with an aperture 49 which extends diametricallytherethrough. Aperture 49 is of rectangular transverse crosssection butthe side walls 51, 52 are convex. An actuating lever 53 is mountedwithin slot 27 in rotor 15 and extends into aperture 49. It is retainedin position by means of a flat circular spring clip 54 mounted in groove22 on rotor 15.

Lever 53 is provided with a portion 56 which engages a forward side face57 of aperture 49 so that the lever is pivotal about the point ofcontact. The lower end 59 of the lever bears against face 52 of aperture49. The other end 61 of the lever projects forward slightly into thebore 24 associated with slot 27. A helical compression spring 63 ishoused within bore 28 and bears against the end of shaft 47 and the endface of the bore. This spring biases member 46 to a position where theforward face 64 of head portion 48 is slightly rearwardly disposedrelative to the plane defining the end faces 40 of slots 23. The extremerearward position of this movement is established by engagement of aflat face 66 of lever 53 with the rearwardly disposed face 660 of slot2. It will be appreciated that it is possible, by pressing against theend portion 61 of lever 53, to move member 46 against the bias of spring53 to shift the head 48 of member 46 so that the face 64 thereof engagesany element 36 disposed so as to project rearwardly of shoulder 31, tomove such member to its forward position.

Skirt 19 on rotor 15 is provided with a radial tapped bore 67 and an endcap 69 of generally cup-shaped configuration is secured to skirt 19, soas to close the end thereof. The securement is effected by means of ascrew 71 which passes through an opening 72 in the side wall of the capand which is engaged in tapped bore 67. Cap 69 is provided with a slot74 in the transverse wall 75 thereof. Slot 74 is centrally disposed inthe wall and is of elongate rectangular form, extending generallyradially of the axis of rotor 15. A latch actuating member 76,

which is indicated generally by dotted lines, is mounted in the slot 74for rotation together with rotor 15. It is however movable axiallywithin the slot.

The body portion 14 includes a generally cylindrical barrel part 78which has an open rear end 79. The intermediate part 17 of rotor 15 isretained within barrel part 78 and the rotor 15 is supported at one endby engagement of shaft 18 in a bearing 83 and at the other end byengagement of the skirt portion 19 in a bearing 84 provided on a bearingmember 86 mounted within barrel 78. Bearing member 86 is of generallycup-shaped configuration and is removably held in position by.

means of a circular spring clip retained in an annular groove 88 on theinner surface of barrel portion 78.

A pair of abutment members 91, 92 are held in position within barrel 78,being held between a step 93 on the interior of the barrel and marginaledge portion 94 of bearing member 86. These abutment members are ofcomplementary form and are shown in detail in FIG. 15. Each has asemi-circular outer surface 97 and a semi-circular internal surface 98.When the two members are assembled together (FIG. 4) they are locatedpositively within the barrel 78 by means of a rib 99 on the interior ofthe barrel which engages a recess 101 defined by two adjacent cut outportions 102 on the members. The interior surfaces 98 of the two members91, 92 together define a circular opening 103 through which theintermediate portion 17 of the rotor passes. This circular opening is ofonly slightly greater diameter than the internal diameter of portion 17at groove 21 and abutment members 91, 92 project into groove 21. Eachabutment member 91, 92 is provided with five notches 104 in surface 98and these are disposed so that when the two members are mounted inposition the notches are disposed at 10 of 11 equi-angularly disposedpositions. The positions thus correspond to the positions of the 10elements 36.

As will be apparent from a consideration of FIGS. 2, 3, and 4 forexample, the dispositions of the abutment members 91, 92 is such thatthe rotor may be prevented from rotation, by engagement of any element36 with the side walls of an associated notch 104, whenever that elementis in a lengthwise position such that the cut out portion 37 therein isnot aligned with the members 91, 92 and groove 21. However when suchelement is moved to its other lengthwise position the cut out portion 37thereon will be aligned with the groove 21 and members 91, 92 androtation of the rotor will not be prevented by that element.

The transverse wall 81 on lock body 14 is provided with 11 equi-spacedcircular apertures 106. These are axially aligned respectively with theadjacent ends of the elements 36 and with the end 61 of lever 53.

The exterior surface of bearing 83 is provided with a series of 11lengthwise extending grooves 107 these being radially aligned with therespective apertures 106. The purpose of these grooves is describedhereinafter. The forward end of bearing 83 is provided with an elongatepart-circumferential slot 108 and pin 58 on rotor 15 is engaged withinthis slot. The length of the slot is such as to limit the rotation ofrotor 15 to extreme positions approximately apart.

The forward end of bearing 83 is provided with a slot 109 which extendsrearwardly and inwardly from the end face thereof. A locking member 111is engageable in this slot and in the slot 32 in rotor 15. Lockingmember 1 l 1 is illustrated in FIG. 20. It is of generally hook-shapedconfiguration comprising a pair of limbs 113, 114 which extend generallyparallel to each other an which are connected by a bridge 116. Limb 1 14is longer than limb 1 13 and is enlarged at its free end, the rootportion of limb 114 being cut away as indicated by reference numeral 118 to define a reduced section portion. Member 111 is slidable in slot109 to a position (FIG. 8 for example) in which the bridge portion 116is engaged within the two slots 32 and 109 to lock the rotor to thebody. This locked position corresponds to a position in which the pin 58is at the extreme clockwise extent of its allowed movement in slot 108and in which that bore 24 in rotor 15 into which lever 53 is engaged isaligned with one of the apertures 106. The latter aperture 106 isidentified by a mark 117 on a forwardly extending annular flange portion1 19 of transverse wall 81 on body 14.

The locking member 111 is movable forwardly from the position in whichit locks the rotor to a position in which the bridge portion 116 is nolonger engaged within slot 32, thereby freeing the rotor for rotation.The forward end of bearing 83 is provided with an inwardly projectinglip 1 19 and, in the last mentioned position of member 111, the cut outportion 118 accommodates this lip to enable the rotor to turn. This lastcondition is illustrated in FIG. 2 for example.

Knob structure 110 comprises two interconnected parts 121 and 122 whichare illustrated respectively in FIGS. 17 and 18. Part 122 is ofgenerally cup shaped configuration, having a cylindrical wall 123,closed at one end by a transverse wall 124, and an outwardly flaredskirt portion 126 extending from the other end of wall 123. Thetransverse end face 127 of flared skirt portion 126 is provided with anotch 128 which extends to the inner surface of the skirt. The internalsurface of the skirt is also provided with a part-circumferential groove129 within which is housed a circular spring clip 131 (FIG. 6). A tappedhole 132 is provided in the end surface 127, this being arranged so thatit communicates, along a side portion thereof, with the inside surfaceof skirt 126. The hole 132 is disposed at a position generallyintermediate the ends of spring clip 131. A rotatable slotted member 133is received in tapped hole 132. Member 133 has a flat longitudinalsurface 134 so that, depending upon the rotational position of themember in hole 132, the-degree of projection of the side thereof intothe the interior of part 122 may be varied. When the member extends intothe interior, it bears against spring clip 131 to move the spring clippartially out of groove 129.

Part 121 of knob 110 comprises two integral generally annular parts 136,137 having a common internal diameter but defining a stepped outerdiameter. The internal surface is defined by a bore 137 which receivesbearing 83. There is provided on the external surface of portion 136, apart circumferential groove 138 and also a radially extending projection139 of complementary configuration to the notch 128 in part 122.

Part 121 is locatable within part 122 and relative rotation of the twomembers is prevented by interengagement of projection 139 and notch 128.The parts are secured together by turning screw 132 to force spring 131radially inwardly at a point intermediate its ends, so that it ispartially engaged within both grooves 138 and 129. This may be effected,after the two parts have been positioned together on hearing 83, byinserting a screw driver through a hole 115 in transverse wall 81 ofbody 14.

The reduced diameter portion of portion 137 extends within cylindricalportion 123 of part 122 but in spaced relation thereto.

A sleeve 141 of generally cylindrical form is interposed betweenportions 137 and 123. A disc 142 is mounted within cylindrical part 123and is resiliently biased in a rearward direction by a helicalcompression spring 144 interposed between the disc and the end wall 124of knob part 122. The disc 142 is normally resiliently biased againstthe forward end surface 100 of bearing 83 but is movable away from thissurface by axial forward movement of knob 110 so that the end surface143 of sleeve 141 engages the disc.

Part 121 of knob 110 is provided with two radially extending notches 146in the forward faces thereof. The axes of these are disposed 90 apartand are of complementary form to the outer surface of pin 58 so that, bymanipulation of knob 110, pin 58 may be received in one of these notches146 to couple knob 110 and rotor together for rotation.

The interior bore 137 of part 121 is provided with a longitudinallyextending slot 148 which extends from end to end thereof, and with anannular slot 149 which communicates with slot 148. As will be apparentfrom FIG. 7, bearing 83 is provided with a pin 151 on its externalsurface. This pin is engageable within slots 148 and 149 by appropriatelongitudinal and rotational manipulation of knob 110 on bearing 83. Part122 of knob 110 is provided on its rearward internal surface with aradial bore 152 (FIG. 12) within which is retained a ball 154. Ball 154is biased, by means of a spring 153 also in bore 152, radially againstthe outer surface of bearing 83. Ball 154 acts as a locating memberwhich selectively allows rotation of knob 110 to preferred positionscorresponding to location of ball 154 in grooves 107 on bearing 83. Whenthe ball is located in a groove 107 knob 110 is guided for longitudinalmovement in the groove and axially of the lock.

The rear face 136 of part 121 of knob 110 is provided with a pin 156which pin is, when ball 154 is engaged in a groove 107, aligned with anaperture 106 in transverse wall 81. The location of this pin isindicated by a mark 158 on the external portion of knob 110. By rotatingknob 110 to each of the preferred positions established by engagement ofball 154 within the separate slots 107 the pin 156 is alignable witheach of the separate apertures 106. The positions of knob 1 10 relativeto mark 117 on body 14 and corresponding to each of these positions areindicated by marks 159 on knob 110.

It will be seen that, by moving knob 110 rearwardly at any of itsestablished rotafional positions pin 156 may enter aperture 106 toextend into that bore 24 in rotor 15 which is aligned therewith, to movethe associated element 36 from its forward to its rearward position andalso, at one rotational position, to engage lever 53 to move resettingmember 46 to engage the elements and push them from the rearward toforward positions.

The operation of the lock will now be described.

FIGS. 2 and 3 show the lock in its closed condition with knob 110 beenmoved forward axially to clear the locking member 111 from slots 32 and109. This movement is accomplished by engagement of the forward annularface 161 on part 121 with the free end of arm 113 of locking member 111. Thus, as the knob reaches the forward extremity of the movement and,as engagement of pin 58 in notch 146 occurs, the bridge part 116 of thelocking member is freed of the slots 32 and 109. Despite this removal ofmember 111, the rotor cannot be turned relative to body 14 becausecertain elements 36 are positioned such that the cut out portions 37thereof are not arranged at the axial position of abutment members 91,92. These elements are indicated, in FIG. 4, by reference numerals 36a.

Assigning the numeral 0 to that rotational portion of knob 110 at whichmarks 117 and 158 are aligned, and numerals l to 10 respectively to thesuccessive progressive anticlockwise rotational positions of knob 110 atwhich the separate marks 159 are aligned with mark 117, the positions ofelements 36a correspond to position 2, 5, and 8 respectively.

To open the lock it is necessary to rotate rotor 15 to thereby rotatelatch actuating member 76 axially through an angle of approximately Todo this it is clear that what is required is to first shift the elements360 from their forward positions to the rear positions to align theslots 37 with the abutrnents 91, 92. This is done by first moving knobrearwardly to position the knob for dialing" (FIG. 8), and then rotatingknob 110 successively to each of the positions 2, 5, and 8 and, at eachposition, moving the knob rearwardly so that the pin 156 passes throughthe adjacent aperture 106 to engage the associated element 36a and pushit rearwardly until the rearrnost face of that element abuts against theseat surface 40 of the associated slot 23 (FIG. 9).

The movement of the knob 110 from the position shown in FIG. 3 to thedialing position, shown in FIG. 8, can only be accomplished when theknob is at its 0 position, since it is only at this position that thepin, 151 is aligned with groove 148. If rearward movement is attemptedat other rotational positions, the pin 151 will abut against the groove149 thereby prevent ing the movement.

At the dialing position of knob l 10 free rotation of the knob ispossible because pin 151 is clear of both slots 148 and 149.

The order in which the three elements 360 are moved by the dialingoperation is not important but it is important that only these elementsbe shifted since, if one of the elements 36 positioned at the otherlocations is moved, the effect will be to shift this slot 37 thereon outof alignment with abutment members 91, 92 thereby preventing subsequentrotation of rotor 15 by virtue of engagement of the element with theside walls of one of the notches 104.

Once having shifted the required locking elements, knob 110 is rotatedto align marks 1 17 and 158. This alignment ensures that pin 151 isadjacent slot 148 as been shown in FIG. 12. The knob may then bewithdrawn so that pin 58 is engaged in a recess 146 and pin 151 entersslot 148. This occurs in the same manner as is shown in FIGS. 2 and 3.During this movement, the rotor is also unlocked by withdrawal oflocking member 111 as previously described. At the position of fullengagement of pin 58 and recess 146, pin 151 is aligned withcircumferential groove 149 so that the knob l may then be rotated (asbest shown in FIG. 10) in a counterclockwise direction when viewed fromthe front to cause corresponding rotation of rotor and of latchactuating member 76. During this movement pin 151 moves in groove 149and pin 58 moves in slot 108, between the extremities thereof. The latchactuating member 76 may be connected to a suitable latch mechanism whichis actuated by the movement thereof.

To reset the lock, knob 110 is turned to the 0 position, in which pin151 is again aligned with slot 148, by turning the rotor back to theposition it occupied before rotation thereof and aligning pin 156 withthat aperture 106 which is aligned with lever 53. The knob is thenpushed forwardly so that pin 156 engages end 61 of lever 53 so as toforce resetting member 46 forwardly of the lock against spring 63 sothat the head of the actuating member engages the rear faces of thevarious locking elements to position them at their forward positionsthereby. locking the rotor. This operation is illustrated in FIG. 11.

The described lock is designed to prevent the lock from reaching certainundesired conditions due to improper manipulation, and the means wherebythis result is achieved is now described. It will be noted from FIG. 10,for example, that once the engagement of pin 58 with recess 146 hastaken place, and the knob is turned, the knob cannot be moved in arearward direction because of engagement of the pin 151 in groove 149.Thus, once the rotor has been freed, and turned, it is not possible toengage pin 156 through an aperture 106 without first returning the knobto the 0 position in which marks 117 and 158 are aligned, i.e., theposition in which pin 151 is again within groove 148. Whenever pin 151is within groove 149, the knob and rotor are locked together forrotation together and lengthwise reciprocation of knob 110 is precluded.lf groove 149 and pin 151 were not provided, it would be possible forthe rotor, once having been freed and turned by knob 110, to be held inthat turned position and, when the knob was returned to its 0 positionand the resetting maneuver completed, instead of lever 53 beingoperated, one of the elements 36 would instead be moved thus locking therotor in its open position. It would be difficult to free the rotor fromthis condition since the normal lock combination 2, 5, 8 would notsufi'ice to unlock it.

While the above arrangement ensures that rotor 15 is always returned toits 0 position immediately before the resetting operation can be carriedout it does not ensure that the rotor will be in this 0 position whenthe maneuver is carried out. There remains still the possibility thatthe rotor could again be turned back after disengagement of the pin 58from recess 146 but immediately before the resetting operation wascarried out. Locking element 111 avoids this difficulty since itoperates to lock the rotor in the 0 position when it is returned to thatposition by knob 1 10. That is, as soon as pin 151 leaves groove 149,the rotor is locked by engagement of the locking member. The pin 151 andmember 111, together with their cooperating grooves and slots thusprovide protection against improper use of the lock; particularlyagainst rotational manipulation of the latch actuating member otherwisethan in consequence of movement of knob 1 10.

The lock may be used to operate a spring loaded latch arrangement inwhich case the rotor 15 would normally be returned to its 0 positionafter actuation of the latch. This is not essential however.

Resetting of the lock can, in the present embodiment, be accomplished bymanipulation of latch actuating member 76. That is to say, by pushingthe latch axially forwardly it can be arranged to bear against resettingmember 46 to effect resetting.

The lock, in the form described, is arranged for anticlockwiseunlatching movement of latch actuating member 76. However, the lock caneasily be adapted to clockwise movement by removing pin 58 from the bore35 in which it is shown engaged and inserting it in the bore 34.

The combination" of the lock may be altered at will merely by reversingthe longitudinal orientation of desired elements A particular advantageof the lock is that it is possible to incorporate into it an alarmsystem to enable an indication to be given when the lock is tamperedwith. To do this, an electric switch is secured within rotor 15. Theswitch is arranged to be actuated by rotor 15 when it moves resettingmember 46 to reset the lock. The switch is connected into an electriccircuit so that operation thereof causes a suitable alarm indication,such as the ringing of a bell.

Now, if even a single element 36 of the lock is moved, the lock cannotbe opened without a subsequent resetting operation so that, in practice,it is practically impossible to open the lock without setting off thealarm, unless one has a knowledge of the lock combination. It should benoted that if only a single unsuccessful attempt to open the lock ismade without a following resetting operation, it will subsequently bepossible to detect that an attempt was made, since it will proveimpossible to open the lock, even with a knowledge of the correctcombination, without resetting and consequent operation of the alarm.

If the lock is fitted to, say, a safe door, it is possible to arrange asuitable switch within the safe so that the alarm system can be turnedoff temporarily after opening to allow a following resetting withoutoperation of the alarm.

It will be appreciated that there is little prospect of opening thedescribed lock in a reasonable period of time without a knowledge of theparticular positions of the locking elements 36. Because of thedescribed construction of the locking elements it is not possible toobserve, as by listening, whether each locking element is being movedinto or out of a locking condition when shifted by movement of knob sothat no assistance in unlocking the lock can be obtained by aural means.

Although there is only a comparatively small number of actuatingelements in the described example there are a great number of possiblelock combinations" which may be selected by appropriate positioning ofelements 36. Larger locks could of course be constructed having muchgreater numbers of combinations if desired.

1 claim:

1. A combination lock having a casing structure having a plurality ofabutments, a rotor mounted for rotation within said structure, aplurality of locking elements carried in openings arranged about theaxis of said rotor and substantially parallel to the axis thereof,actuating means and resetting means, said locking elements each beingslidably movable in said openings between first and second locations andeach, in one of these locations, preventing substantial rotation of saidrotor within said casing structure by cooperating with said abutmentsand in the other location being cleared of said abutrnents and notprecluding such rotation,

said actuating means being operable to move said elements or anyselected one or more thereof one by one from the first location to thesecond location; said actuating means comprising a knob mounted on saidcasing structure for rotation about the axis of said rotor and relativeto the rotor, said knob also being movable axially of the casingstructure and being provided with a projecting actuating member which isselectively movable by axial movement of the knob so as to efi'ect saidmovement of the locking elements by engagement with facing ends of thelocking elements; said resetting means being operable to move all ofsaid locking elements from said second to said first location andincluding a member having a stem portion which is slidable in agenerally axial bore in said rotor and a head, said head being movableaxially in said bore and towards said knob to engage end surfaces ofsaid elements opposite to said facing ends to effect the movementthereof from said second location to said first location, and saidresetting member being resiliently biased in a direction away from saidknob, the lock also including a lever pivotal at a point intermediateits length, about an axis which is substantially fixed relative to saidrotor, one end thereof being engageable with said stem and the other endbeing positioned so that it may be depressed axially away from saidknob, by engagement therewith by said actuating member.

2. A combination lock as claimed in claim 1 wherein said casingstructure is provided with a wall extending transversely of the axis ofrotation of the rotor intermediate said knob and said elements andprovided with a plurality of apertures therethrough, the apertures beingpositioned so that when the rotor is in a locked condition, being acondition in which it is prevented from rotation within the casingstructure by engagement of one or more of said locking elements with acooperating abutment or abutrnents, the said apertures arelongitudinally aligned each with a separate one of said openings, saidactuating member being moved through said apertures to effect saidmovement of the locking elements and through one of said apertures or afurther aperture in said wall to effect said depression of said lever.

3. A combination lock as claimed in claim 2 wherein the said other endof the lever and the said openings are equi-angularly disposed in saidrotor and all of the said apertures including the said further apertureare correspondingly arranged in said wall.

4. A combination lock as claimed in claim 3 wherein said knob is mountedfor rotation upon a boss extending from said wall in an oppositedirection to said elements, which knob being freely rotatable on saidboss and movable axially relative thereto to a coupled position furtheraway from said wall than a position in which said actuating member isjust clear from said wall, said rotor having an extension extendingcoaxially within said boss, and said knob engaging said rotor extension,in said coupled position, to couple said rotor to said knob for.rotation together as a unit.

5. A combination lock as claimed in claim 4 wherein the said extensionis provided with a first pin or other projection which extends through apart circumferentially extending opening in said boss and is engageablewith a recess in a transversely extending portion of said knob to effectsaid coupling between the rotor and knob.

6. A combination lock as claimed in claim 5 wherein there is providedmeans for preventing said coupling from taking place except when saidknob is positioned so that said actuating member is aligned with aparticular one of said apertures and further aperture.

7. A combination lock as claimed in claim 6 wherein said means forpreventing said coupling comprises a second pin or projection fixed uponthe outer surface of said boss and a lengthwise extending slot formed inthe inner periphery of said knob, said second pin or projection beingreceived in said lengthwise extending slot during movement of said knobto said coupled position and when the said actuating member is.

aligned with said one particular aperture, but movement of the knob tothe coupled position being precluded, when said actuating member is notaligned with said one particular aperture, by engagement of said secondpin or projection with said transversely extending portion.

8. A combination lock as claimed in claim 7 and including means forpreventing decoupling of the knob and rotor except when said knob ispositioned so that said actuating member is aligned with said oneaperture.

A combination lock as claimed in claim 8 wherein said means forpreventing decoupling comprises a circumferential or partcircumferential groove on the inner periphery of said knob in which saidsecond pin or projection is accommodated during turning of the coupledknob and rotor.

10. A combination lock as claimed in claim 5 wherein there is providedlocking means locking said rotor relative to said casing structure in adisposition in which said one particular aperture is aligned with thesaid other end of said lever, said locking means operating independentlyof said locking elements when said knob is decoupled and releasing uponmovement of said knob to said coupled position.

11. A combination lock as claimed in claim 10 wherein rotation of saidrotor in said casing structure is limited, by engagement of said firstpin or other projection with opposite ends of said part-circumferentialopening, for rotation in one direction away from said disposition, androtation in the opposite direction back to said disposition.

12. A combination lock as claimed in claim 10 wherein said locking meansincludes a lengthwise extending first slot in said rotor extension, saidfirst slot extending to that end of the rotor extension remote from saidwall, a lengthwise extending second slot in said boss, extending to theend thereof remote from said wall, and a locking member having an armthereof retained in said first slot and a transverse portion extendingoutwardly of the axis of the rotor; the said locking member beingslidable in said first slot to and from a locked condition in which saidtransversely extending portion is engaged in the second slot to effectlocking.

13. A combination lock as claimed in claim 12 wherein said locking meansfurther includes means resiliently biasing said locking member towardssaid wall and operating to displace the locking means so that saidtransverse portion enters said second slot when the rotor is positionedat said disposition and the knob is advanced towards said wall; saidtransverse portion being engageable by the transversely extendingportion of said knob when said knob is moved to said coupled position tomove said locking member in a direction away from said wall to disengagesaid transverse portion from said second slot.

14. A combination lock as claimed in claim 13 wherein said lever isengaged in a generally radial third slot in said rotor, said third slotextending from the outer surface of the rotor into said bore, and saidlever being provided with shaped surfaces which engage axially spacedsurfaces of said third slot whereby the lever is pivotable about thesesurfaces, the lever being removably retained in the third slot by aremovable clip which closes the outer end thereof.

15. A combination lock as claimed in claim 14 wherein said abutmentsextend inwardly and generally radially of said casing structure, saidlocking elements each having a notch extending inwardly of a surfacethereof which is disposed radially outerrnost of the axis of rotation ofthe rotor, each said notch, when the corresponding locking element is inits location allowing rotation of the rotor, being disposed at the axiallocation of said abutments, and clear of these during rotation of therotor, each said notch being, when the corresponding locking element isin its rotation precluding location, axially displaced of saidabutments; rotation of the rotor being precluded by engagement of anunnotched portion of the locking element with an abutment.

16. A combination lock as claimed in claim 15 wherein one side face ofeach said notch is disposed in a transverse plane of the associatedlocking element, this plane being disposed at a point midway between theaxial ends thereof.

III

1. A combination lock having a casing structure having a plurality ofabutments, a rotor mounted for rotation within said structure, aplurality of locking elements carried in openings arranged about theaxis of said rotor and substantially parallel to the axis thereof,actuating means and resetting means, said locking elements each beingslidably movable in said openings between first and second locations andeach, in one of these locations, preventing substantial rotation of saidrotor within said casing structure by cooperating with said abutmentsand in the other location being cleared of said abutments and notprecluding such rotation, said actuating means being operable to movesaid elements or any selected one or more thereof one by one from thefirst location to the second location; said actuating means comprising aknob mounted on said casing structure for rotation about the axis ofsaid rotor and relative to the rotor, said knob also being movableaxially of the casing structure and being provided with a projectingactuating member which is selectively movable by axial movement of theknob so as to effect said movement of the locking elements by engagementwith facing ends of the locking elements; said resetting means beingoperable to move all of said locking elements from said second to saidfirst location and including a member having a stem portion which isslidable in a generally axial bore in said rotor and a head, said headbeing movable axially in said bore and towards said knob to engage endsurfaces of said elements opposite to said facing ends to effect themovement thereof from said second location to said first location, andsaid resetting member being resiliently biased in a direction away fromsaid knob, the lock also including a lever pivotal at a pointintermediate its length, about an axis which is substantially fixedrelative to said rotor, one end thereof being engageable with said stemand the other end being positioned so that it may be depressed axiallyaway from said knob, by engagement therewith by said actuating member.2. A combination lock as claimed in claim 1 wherein said casingstructure is provided with a wall extending transversely of the axis ofrotation of the rotor intermediate said knob and said elements andprovided with a plurality of apertures therethrough, the apertures beingpositioned so that when the rotor is in a locked condition, being acondition in which it is prevented from rotation within the casingstructure by engagement of one or more of said lOcking elements with acooperating abutment or abutments, the said apertures are longitudinallyaligned each with a separate one of said openings, said actuating memberbeing moved through said apertures to effect said movement of thelocking elements and through one of said apertures or a further aperturein said wall to effect said depression of said lever.
 3. A combinationlock as claimed in claim 2 wherein the said other end of the lever andthe said openings are equi-angularly disposed in said rotor and all ofthe said apertures including the said further aperture arecorrespondingly arranged in said wall.
 4. A combination lock as claimedin claim 3 wherein said knob is mounted for rotation upon a bossextending from said wall in an opposite direction to said elements,which knob being freely rotatable on said boss and movable axiallyrelative thereto to a coupled position further away from said wall thana position in which said actuating member is just clear from said wall,said rotor having an extension extending coaxially within said boss, andsaid knob engaging said rotor extension, in said coupled position, tocouple said rotor to said knob for rotation together as a unit.
 5. Acombination lock as claimed in claim 4 wherein the said extension isprovided with a first pin or other projection which extends through apart circumferentially extending opening in said boss and is engageablewith a recess in a transversely extending portion of said knob to effectsaid coupling between the rotor and knob.
 6. A combination lock asclaimed in claim 5 wherein there is provided means for preventing saidcoupling from taking place except when said knob is positioned so thatsaid actuating member is aligned with a particular one of said aperturesand further aperture.
 7. A combination lock as claimed in claim 6wherein said means for preventing said coupling comprises a second pinor projection fixed upon the outer surface of said boss and a lengthwiseextending slot formed in the inner periphery of said knob, said secondpin or projection being received in said lengthwise extending slotduring movement of said knob to said coupled position and when the saidactuating member is aligned with said one particular aperture, butmovement of the knob to the coupled position being precluded, when saidactuating member is not aligned with said one particular aperture, byengagement of said second pin or projection with said transverselyextending portion.
 8. A combination lock as claimed in claim 7 andincluding means for preventing decoupling of the knob and rotor exceptwhen said knob is positioned so that said actuating member is alignedwith said one aperture.
 9. A combination lock as claimed in claim 8wherein said means for preventing decoupling comprises a circumferentialor part circumferential groove on the inner periphery of said knob inwhich said second pin or projection is accommodated during turning ofthe coupled knob and rotor.
 10. A combination lock as claimed in claim 5wherein there is provided locking means locking said rotor relative tosaid casing structure in a disposition in which said one particularaperture is aligned with the said other end of said lever, said lockingmeans operating independently of said locking elements when said knob isdecoupled and releasing upon movement of said knob to said coupledposition.
 11. A combination lock as claimed in claim 10 wherein rotationof said rotor in said casing structure is limited, by engagement of saidfirst pin or other projection with opposite ends of saidpart-circumferential opening, for rotation in one direction away fromsaid disposition, and rotation in the opposite direction back to saiddisposition.
 12. A combination lock as claimed in claim 10 wherein saidlocking means includes a lengthwise extending first slot in said rotorextension, said first slot extending to that end of the rotor extensionremote from said wall, a lengthwise extending second slot in said boss,extendIng to the end thereof remote from said wall, and a locking memberhaving an arm thereof retained in said first slot and a transverseportion extending outwardly of the axis of the rotor; the said lockingmember being slidable in said first slot to and from a locked conditionin which said transversely extending portion is engaged in the secondslot to effect locking.
 13. A combination lock as claimed in claim 12wherein said locking means further includes means resiliently biasingsaid locking member towards said wall and operating to displace thelocking means so that said transverse portion enters said second slotwhen the rotor is positioned at said disposition and the knob isadvanced towards said wall; said transverse portion being engageable bythe transversely extending portion of said knob when said knob is movedto said coupled position to move said locking member in a direction awayfrom said wall to disengage said transverse portion from said secondslot.
 14. A combination lock as claimed in claim 13 wherein said leveris engaged in a generally radial third slot in said rotor, said thirdslot extending from the outer surface of the rotor into said bore, andsaid lever being provided with shaped surfaces which engage axiallyspaced surfaces of said third slot whereby the lever is pivotable aboutthese surfaces, the lever being removably retained in the third slot bya removable clip which closes the outer end thereof.
 15. A combinationlock as claimed in claim 14 wherein said abutments extend inwardly andgenerally radially of said casing structure, said locking elements eachhaving a notch extending inwardly of a surface thereof which is disposedradially outermost of the axis of rotation of the rotor, each saidnotch, when the corresponding locking element is in its locationallowing rotation of the rotor, being disposed at the axial location ofsaid abutments, and clear of these during rotation of the rotor, eachsaid notch being, when the corresponding locking element is in itsrotation precluding location, axially displaced of said abutments;rotation of the rotor being precluded by engagement of an unnotchedportion of the locking element with an abutment.
 16. A combination lockas claimed in claim 15 wherein one side face of each said notch isdisposed in a transverse plane of the associated locking element, thisplane being disposed at a point midway between the axial ends thereof.